Decline Of Vegetation Research Articles

Decline and Passive Restoration of Forest Vegetation Around the Yeocheon Industrial Complex of Southern Korea

This study was carried out to clarify the vegetation decline due to air pollutants emitted in the process of industrial activities and the passive restoration of the vegetation due to socioeconomic changes after economic growth. To achieve this goal, we investigated the spatial distribution of vegetation, differences in species composition and diversity among vegetation types different in damage degree, vegetation dynamics, the age structure and annual ring growth of two dominant plant species, and the landscape change that occurred in this area over the last 50 years. Plant communities tended to be spatially distributed in the order of grassland, shrubland (dominated by Styrax japonicus Siebold and Zucc. community), and forests (dominated by Pinus thunbergii Parl. and Pinus densiflora Siebold and Zucc. communities), with increasing distance from the pollution source. The result of stand ordination based on vegetation data reflected the trend of such a spatial distribution. Species richness evaluated based on the species rank dominance curve was the highest in shrubland and the lowest in grassland; species richness in forests was intermediate. The size class distribution of woody plant species in four plant communities composing three vegetation types showed the possibility of them being replaced by forest in the late successional stage. However, the density of successor trees was relatively low, whereas the density of shrubby plants, which are resilient to air pollution, was very high. The age class distribution of a dominant species forming shrubland and pine forest showed that most of them were recruited after industrialization in this area. The period when young individuals in both vegetation types were recruited corresponded to the period when the annual ring growth of the pine trees that survived air pollution was reduced. An analysis of the landscape change in this area indicated that coniferous forest and agricultural field decreased greatly, whereas industrial area, residential area, mixed forest, and broadleaved forest showed increasing trends since construction of the industrial complex. As a result, the decrease in coniferous forest is usually due to vegetation decline and partially to succession, as the pine trees dominating the forest are not only sensitive to air pollution but are also shade-intolerant. The increase in mixed and broadleaved forests reflects vegetation decline or succession. Vegetation decline progressed for about 30 years after the construction of the industrial complex; it has begun to be restored passively since then, although the change has been slow. These results are in line with the environmental Kuznets curve hypothesis that environmental degradation increases in the early stages of economic growth to a certain point, and, after a turning point, economic development leads to environmental improvements—thus, there is an inverted U-shaped relationship between economic growth and environmental degradation.

Detecting and Analyzing Land Use and Land Cover Changes in the Region of Al-Jabal Al-Akhdar, Libya Using Time-Series Landsat Data from 1985 to 2017

The region of Al-Jabal Al-Akhdar in northeastern Libya has undergone rapid, wide-ranging changes in the land use and land cover (LULC) intensified by the conversion of natural resources for food purpose, urbanization, and other socioeconomic benefits. This study examined the use of geographic information system (GIS) and remote sensing techniques to gain a quantitative understanding of the spatiotemporal dynamics of LULC. In addition, the major factors behind LULC changes and decline of natural vegetation in the region were analyzed. A post-classification comparison approach was used to detect LULC changes in the study area between 1985 and 2017 using four Landsat images from 1985, 2000, 2010, and 2017. The observed changes were indicative of a decrease in the expanse of the natural Mediterranean forest which lost 9018 ha over 32 years, 39% of its total area, with the highest deforestation rate registered between 2010 and 2017 estimated at 513 ha. year−1. Orchards and rain-fed agriculture lands gained 4095 ha, which matches 55% of initial area, whereas the land under irrigated crops increased by 2266 ha, about 85% of the original area. The area of urban and built-up land in 2017 was more than double in 1985 and achieved the highest urbanization rate between 2010 and 2017 at 203 ha.year−1. Results indicate an unstable trend of bare and low vegetation lands which generally increased by about 50%. From the outcomes of this research, it is strongly recommended that urgent measures be taken to conserve the natural forest and to achieve a rational use of agricultural land in the region of Al-Jabal Al-Akhdar.

Contribution of Deforestation to Severe Flooding in Southeast Parts of the Caspian Sea: A Case Study with NDVI Analysis

Iran has been faced with increase in flooding cases during the past 60 years. The human activities have been considered as a devastating factor in the environmental change causing the occurrence of severe flooding cases during past decades. On August 11, 2001, a relatively severe rainfall in the south east of Caspian Sea led to the occurrence of a severe deadly flooding in Golestan province and some parts in northern Khorasan province have been unprecedented in Iran over the past century. The destructive extent of flooding in the urban and rural areas reached about 5,000 km2. Here, the synoptic surface and upper levels of the weather charts have been analyzed along with the monitoring of half hourly METEOSAT7 images to show the convective clouds development over the area of the study. The total precipitation in this area during the flooding period was reported between 2.5 and 153 mm with the maximum estimation over the center of the storm around less than 250[Formula: see text]mm. Using satellite imagery in 1979 and 2000, vegetation changes and environmental changes have been investigated and shown extensive decline in vegetation. The image processing and Normalized Difference Vegetation Index (NDVI) calculation of the color composite 433 of LANDSAT5 and the color composite 211 of TERRA (MODIS sensor) images between 1998 and 2001 have been revealed significant deforestation around 248,131,534.3[Formula: see text][Formula: see text] over the study, particularly over the rivers’ neighborhood. Also, by assumption of the same precipitation for 1998 and 2001, the discharge rate in flood case of 2001 has been intensified 1.3 times (at 13 percent) larger than that of 1998. This shows the direct impact of the deforestation and land use changes over the study area during 1998–2001.

Investigating Banksia Coastal Woodland Decline Using Multi-Temporal Remote Sensing and Field-Based Monitoring Techniques

Coastal woodlands, notable for their floristic diversity and ecosystem service values, are increasingly under threat from a range of interacting biotic and abiotic stressors. Monitoring these complex ecosystems has traditionally been confined to field-scale vegetation surveys; however, remote sensing applications are increasingly becoming more viable. This study reports on the application of field-based monitoring and remote sensing/(Geographic Information System) GIS to interrogate trends in Banksia coastal woodland decline (Kings Park, Perth and Western Australia) and documents the patterns, and potential drivers, of tree mortality over the period 2012–2016. Application of geographic object-based image analysis (GEOBIA) at a park scale was of limited benefit within the closed-canopy ecosystem, with manual digitisation methods feasible only at the smaller transect scale. Analysis of field-based identification of tree mortality, crown-specific spectral characteristics and park-scale change detection imagery identified climate-driven stressors as the likely primary driver of tree mortality in the woodland, with vegetation decline exacerbated by secondary factors, including water stress and low system resilience occasioned by the inability to access the water table and competition between tree species. The results from this paper provide a platform to inform monitoring efforts using airborne remote sensing within coastal woodlands.

Response and Simulation of Vegetation in Desert Scenic Spot to Tourists’ Trampling Disturbance

A large number of tourists had a devastating effect to the scenic area. Shapotou and Huangshagudu scenic spots in Ningxia were selected as the research areas. The fait accompli method was used to investigate the response of footpath in the above scenic spots to tourists’ stampede interference. Three different angles and different vegetation types of quadrats were set up to simulate tourists’ stampede mode and observe the vegetation recovery after stampede. The results showed that: (1) The tourist trampling disturbance mainly were limited 0-4 meters distance from the tourist trails, but there was difference for different tourist trails. (2) The index of land cover impact ( ILCI ) of the investigating sections indicated the 1 meter distance from tourist trail is seriously disturbed; Because of the palisade on both sides of the plank road, the average value of ILCI in north of Shapotou (investigating section 4) is less than 44.9%.(3)With the increase of tourist activity,the coverage of vegetation decline, the height of plant reduce, the quantity and kinds decrease,soil crust fragmentation increase.(4)Because of different angle of sand dune, the impact of tourist activity to vegetation and soil is different.Vegetation and biological crust of sample C which is the biggest angle suffer from the devastation.(5)Based on limits of acceptable change ( LAC ) visitor questionnaires, the limit of acceptable change in ground coverage was 16.4%. The vegetation coverage should be below this level at desert scenic spots. It shows that there is natural incompatible relationship between tourist demand to the empty and desolate desert and desert ecological management. The results also indicated that the current tourism disturbance had some negative effect on the tourist experience and ecosystem.

Micro level analyses of environmentally disastrous urbanization in Bangalore.

Indian metropolitan (tier I) cities have been undergoing rapid urbanization during the post-globalization era with the unprecedented market interventions, which have led to the rapid land cover changes affecting the ecology, climate, hydrology, and local environment. The unplanned urbanization has given way to the dispersed, haphazard growth at the city outskirts with the lack of basic amenities and infrastructure as the planners lack advance information of sprawl regions. This has necessitated understanding and visualization of urbanization patterns for planning towards sustainable cities. The analyses of urban dynamics during 1973-2017 using temporal remote sensing data reveal 1028% increase in urban area with the decline of 88% vegetation and 79% of water bodies. Consequences of the unplanned urbanization are the increase in greenhouse gas emissions, decline in vegetation cover, loss of groundwater table (from 28 to 300m), contamination of water sources, increase in land surface temperature, increase in disease vectors, etc. An attempt is made to understand the implications of unplanned growth at the micro level by considering the prime growth poles such as Peenya Industrial Estate (PIE), Whitefield (WF), Bangalore South Region (BSR). The spatial analyses reveal the decline of vegetation and open spaces with intense urbanization of 86.35% (in BSR), 87.39% (PIE) and 81.61% (WF) in 2017. WF witnessed the drastic transformation from agrarian ecosystem to a concrete jungle during the past four decades. Spatial patterns of urbanization were assessed through the landscape metrics and rule-based modeling which confirms intense urbanization with single class dominance. Specifically, NP metrics depicts PIE region had sprawl growth till 2003 with numerous patches and is transformed by 2017 it has become to a single dense urban patch. This necessitates appropriate planning strategies to mitigate further erosion of environmental resources and ensure clean air, water, and environment to all residents.

Geo-visualization of landscape dynamics in the proposed mega industrial corridor.

Urbanization is associated with large-scale irreversible landscape changes in response to the demands of burgeoning population, etc. Lack of basic amenities, job, and infrastructures in rural areas often drives migration towards the urbanizing landscapes. Urbanization is resource centric, which involves, large-scale transformation of the landscape with the irreversible impacts on the regional ecology, hydrology, and environment, which is evident from large-scale land cover changes leading to deforestation, encroachment of lakes/water bodies, forest, and farmlands, conversion of agriculture landscapes, etc. damaging the environs. Visualization of urban growth based on the past spatial patterns would help in evolving appropriate policy framework towards the design of sustainable cites for the prudent management of natural resources. Current communication attempts to understand the landscape dynamics along the proposed Mumbai-Pune industrial corridor (with 10 km buffer) through (i) rule-based/non agent-based models (non-ABM) and (ii) agent-based models (ABM) with the evaluation of relative performance of ABM and non-ABM methods. Comparative assessment of the model performance through accuracy assessment and Kappa (relatively significant at p < 0.05) indicates the superior performance of the agent-based model approaches due to its interaction with factors and constraints that allow urban growth in the region. Non-ABM model predicted the growth of 49.69% by 2027 with the decline of vegetation to 9.63%. Compared to this, agent-based model predicted growth in urban landscape to 47.12% and the decline of vegetation to 11.10%. The current research was formulated based on the recommendations of the deliberation between academia and stakeholder industries that are likely to be benefitted by the implementation of the industrial corridor. The research outcome also helps local planning authorities in advance visualization of urban dynamics to design sustainable urban regions with the provision of appropriate infrastructure and basic amenities.

The response of water balance components to land cover change based on hydrologic modeling and partial least squares regression (PLSR) analysis in the Upper Awash Basin

Study regionUpper Awash basin at the headwater of Awash River. Study focusComprehensive assessment of land cover (LC) change effect on the water balance components using integrated approaches of hydrologic modeling and partial least squares regression (PLSR) provides better understandings of the impact of recent development activities on water resources. The SWAT model was validated at five subbasins and used to simulate the water balance and hydrologic response to LC changes at multiple temporal and spatial scales. PLSR was used to evaluate the significance of the relative influence of LC classes on the hydrologic components. New hydrological insights for the regionBased on the multitemporal LC change detections, Upper Awash basin is characterized by the decline of natural vegetation due to the swelling rise of cropland and urbanization. The monoplot of PLSR components exhibited that groundwater is highly correlated with the forest areas and lateral flow is strongly correlated with pasture, whereas, surface runoff is significantly attributed to the change in urban and cropland. The Variable Importance for the Projection (VIP) and PLSR weight (w) revealed that the decline of groundwater is mainly due to urban (VIP = 1.34 and w=-0.55), whereas, the change in forest area enhanced groundwater (VIP = 1.04 and w = 0.47). The study provides valuable information on the contribution of particular LC to change in water balance which is vital for improved water resources management.

Experimental evidence for the decline of submerged vegetation in freshwater ecosystems by the invasive Chinese mitten crab (Eriocheir sinensis)

The Chinese mitten crab (Eriocheir sinensis) is a damaging invader which is designated as a species of Union Concern within the European Union. A negative impact of the crabs on macrophyte vegetation in lowland rivers is suspected but not yet proven or quantified. We have performed a mesocosm study that combines a density gradient of Chinese mitten crabs (0, 0.3, 1.0 and 2.5 ind. m−2) with chemical stress (2350 µg EDTA L−1 + 258 µg glyphosate L−1) or light limitation stress (− 70% irradiance compared to control) on water plants (Myriophyllum spicatum). The results clearly demonstrate that the crabs are capable of removing plant shoots effectively which can lead to a complete elimination of the vegetation. Generally, the higher the crab density, the sooner the plants started to disappear and the sooner the vegetation was completely removed. Additional light and chemical stress accelerated this process: plant disappearance at a crab density of 0.3 ind. m−2 compared to 1.0 ind. m−2 in the control treatments. Video recording, plant strength and crab pinch strength measurements and stable isotope signatures of δ13C and δ15N in the Chinese mitten crabs and their possible food sources showed that directly eating the plants is causing only minor damage to the plants. Most damage comes from the movement of the crabs and crab–crab interactions during which they use their chelae to grasp the shoots. We conclude that a decline of vegetation as a consequence of Chinese mitten crab behaviour can be a realistic scenario in freshwater ecosystems and warrants close attention and monitoring. Being primary producers and ecological engineers, macrophytes are key species in these ecosystems, whose services are lost when they disappear and are difficult to restore.

Invasion increasing risk of Al Jawahir Wadi lentic habitats by 'Pistia stratiotes' L. (North-Central Morocco)

Draining of wetlands and their inadequate planning contribute greatly to the decline of hygrophilous vegetation. The arrival of invasive hygrophilous species, as noted recently for Pistia stratiotes L. in Al Jawahir Wadi (North Central Morocco) could also aggravate this situation. Surveys carried out in the watershed of this river show that P. stratiotes form spontaneous communities over a river-length of 10 km, twice of that reported in 2012, in spite of measures taken to limit its spread. Plants description on the basis of vegetative and reproductive criteria ascertains the permanent presence of this species upstream of the wadi, and reveals a succession of factors causing its intermittent suffocation downstream, including hydrological and planning hazards, and water pollution. The decontamination endeavors of Al Jawahir River and the exceptional propagating power of this species would represent a real threat to local water bodies for long.

Spatio-temporal Variations in Aquatic Vegetation Cover and the Potential Influencing Factors in Lake Hongze Based on MODIS Images

Aquatic vegetation is an important part of lake ecosystems and plays a vital role in improving water quality and maintaining biodiversity. At present, China's lakes are facing eutrophication and the degradation of aquatic vegetation. The monitoring of temporal and spatial variations in aquatic vegetation and elucidating the main influencing factors are of great significance for protecting aquatic vegetation and restoring eutrophic lake ecosystems. Therefore, we introduced the Vegetation Present Frequency (VPF) method to extract data on aquatic vegetation and combined this with meteorological factors and human activities to analyze the temporal and spatial in Lake Hongze based on MODIS data from 2007 to 2017. The VPF of aquatic vegetation in Lake Hongze showed clear seasonal and interannual variations. The VPF was significantly higher in spring and summer than in autumn and winter (P<0.05, one way-ANOVA). The maximum VPF of 0.43 occurred in June but the minimum VPF of 0.21 was recorded in January. The VPF from April to October, during the growing season of aquatic vegetation, was significantly higher than in other months. The annual mean VPF of the northern lake area (Z1) decreased significantly (R2=0.56, P<0.01), ranging from the highest value of 0.50 in 2008 to the lowest value of 0.27 in 2016 (a decrease of 45.8%), indicating a significant loss of aquatic vegetation. Spatially, the VPF of Lake Hongze decreases from the coastal zone to the open water, and the VPF values of the northern (Z1) and western sub-lakes (Z2) are higher than that of other lakes segments (Z3-Z5). The interannual variation in VPF for the entire lake was not significantly affected by annual mean temperature, annual precipitation, annual mean wind speed, or annual sunshine duration (P>0.05), indicating that meteorological factors have little influence on interannual variation of aquatic vegetation in this lake. However, total suspended matter concentration was significantly negatively correlated with VPF in Z1 area (R2=0.48, P<0.01), with strong sand-mining activities occurring in this area. These results indicate that the increase of total suspended matter concentrations caused by sand mining is an important driving factor in the decline of aquatic vegetation in the Z1 segment.

Greenhouse gas and energy fluxes in a boreal peatland forest after clear-cutting

Abstract. The most common forest management method in Fennoscandia is rotation forestry, including clear-cutting and forest regeneration. In clear-cutting, stem wood is removed and the logging residues are either removed or left on site. Clear-cutting changes the microclimate and vegetation structure at the site, both of which affect the site's carbon balance. Peat soils with poor aeration and high carbon densities are especially prone to such changes, and significant changes in greenhouse gas exchange can be expected. We measured carbon dioxide (CO2) and energy fluxes with the eddy covariance method for 2 years (April 2016–March 2018) after clear-cutting a drained peatland forest. We observed a significant rise (23 cm) in the water table level and a large CO2 source (first year: 3086±148 g CO2 m−2 yr−1; second year: 2072±124 g CO2 m−2 yr−1). These large CO2 emissions resulted from the very low gross primary production (GPP) following the removal of photosynthesizing trees and the decline of ground vegetation, unable to compensate for the decomposition of logging residues and peat. During the second summer (June–August) after the clear-cutting, GPP had already increased by 96 % and total ecosystem respiration decreased by 14 % from the previous summer. The mean daytime ratio of sensible to latent heat flux decreased after harvesting from 2.6 in May 2016 to 1.0 in August 2016, and in 2017 it varied mostly within 0.6–1.0. In April–September, the mean daytime sensible heat flux was 33 % lower and latent heat flux 40 % higher in 2017, probably due to the recovery of ground vegetation that increased evapotranspiration and albedo of the site. In addition to CO2 and energy fluxes, we measured methane (CH4) and nitrous oxide (N2O) fluxes with manual chambers. After the clear-cutting, the site turned from a small CH4 sink into a small source and from N2O neutral to a significant N2O source. Compared to the large CO2 emissions, the 100-year global warming potential (GWP100) of the CH4 emissions was negligible. Also, the GWP100 due to increased N2O emissions was less than 10 % of that of the CO2 emission change.

Assessment of forest health status using a forest fragmentation approach: a study in Patharia Hills Reserve Forest, northeast India

Diverse anthropogenic pressure has led to land use change in the form of decline of vegetation and fragmented habitats. With rising anthropogenic threats, many species are restricted to fragmented and degraded habitats and declining biodiversity. The aim of the study was to understand the forest health status in Patharia Hills Reserve Forest (RF) using land use land cover (LULC) trajectories along with forest cover and fragmentation approach. Landsat TM and OLI images for three particular days of each of the year 1988, 1997 and 2016 were used to assess spatio-temporal variation in forest cover. Fragmentation model was used to examine the patterns of forest fragmentation in the Patharia Hills RF during the study period. The results indicated an overall increase in forest cover (10.52%) along with rise in human settlements and agriculture, while decrease in grasslands between 1988 and 2016. However, the fragmentation analysis revealed that the health of the RF has been deteriorating. Increasing edge effects with declining core areas were the prime indicators of disturbances on the forest. The eastern border of the RF is under tremendous influence of anthropogenic activities and most of the land use land cover change was observed in that side. Human settlements, agriculture, and developmental activities were main contributors to forest fragmentation at that side of the RF, while better protection at the international border area was the major factor to increase forested areas at the western part of the RF. Forest fragmentation has a large impact on biodiversity and increase risks for survival for many species, especially primate and the migratory elephant would suffer more in the study area. Fragmentation habitats would lead to increasing Human–Elephant Conflict (HEC). To control the habitat fragmentation, proper management strategies should be prepared which include afforestation in the perforated areas, reduce anthropogenic pressures, and demarcate the RF for its better protection.

Management of the Effects of Land Use Changes on Urban Infrastructure Capacity: A Case Study of Ruaka Town, Kiambu County, Kenya

Land use change is a major driver to the effects of climate change and other socio-economic and environmental challenges, a major challenge policy makers, planners and urban managers grapple with. Ruaka town is no exception as it faces high rapid land use change with myriad challenges on the management of the effects on urban infrastructure and aggravated by inadequate inter-agencies, coordination and collaboration. The study is an investigation of the effects of land use changes on urban infrastructure (roads, water supply, and wastewater infrastructure). It seeks to answer the drivers of land use changes and document the spatial-temporal land use changes between the years 1988 to 2019, establish their effects on infrastructure. The study establishes decline in vegetation and agriculture and rise in built -up areas which is partially contributed by urbanization and population growth in the area with major land fragmentations and land use conversions. The findings reveal encroachment of development to vegetation and riparian reserves which expose the human population to disasters and calamities in cases of climate change. Lack of approved planning policy has encouraged massive land use changes due to the ad hoc nature of planning using the development control tools which are not documented. The key drivers of land use changes deduced were good accessibility of the area, land speculation for investments, high returns from investments, demand for housing and accommodation and high population growth. The adverse effects on urban infrastructure includes pollution and contamination of water sources, traffic congestion, use of unconventional onsite waste management practices such as pit latrines and septic tanks for waste water management. The study concluded by evolving a management strategy to unravel the challenges through promotion of a sustainable and resilient urban infrastructure. The strategies emphasize on the technical, social, economic, environmental and jurisdictional dimensions.

Bivariate probabilistic quantification of drought impacts on terrestrial vegetation dynamics in mainland China

Frequent droughts in a warming climate may exert more negative influences on ecosystems. Unlike previous studies that have investigated the vegetation response to drought generally in a deterministic way, a copula-based model is developed for quantifying drought impacts on terrestrial vegetation and identifying drought-vulnerable regions for mainland China from a probabilistic perspective in this study. The Normalized Difference Vegetation Index (NDVI) is firstly correlated with the Standardized Precipitation Evapotranspiration Index (SPEI) at varying timescales from 1 month to 24 months to determine the response time of vegetation to water variability. Then, the dependence structure of vegetation vigor and water availability is modeled through the bivariate copula analysis. Furthermore, conditional probabilities of vegetation decline under moderate, severe and extreme drought scenarios are systematically estimated using copula-based conditional probability distributions. Results indicate that spatial patterns of vegetation response time present distinct seasonality, with faster response to water variation in the southern part than in the northern proportion of mainland China during the non-growing season while the inverse pattern is observed for the growing season. The higher conditional probabilities of the below-average vegetation status in the dry condition evidence that water deficits overwhelming water surplus play a more profound role in diminishing vegetation vigor across more than 80% of mainland China. Specifically, when moderate droughts develop into extreme ones, the average probability of vegetation status below the 50th percentile escalates by 6.9%. Moreover, extreme droughts are noted to exaggerate probabilities of vegetation activity falling below the increasingly lower (40th, 30th, 20th and 10th) percentiles by 8.8%, 10.8%, 12.7% and 13.7% in comparison with moderate counterparts, thereby suggesting higher likelihood of the deteriorating drought conditions inducing vegetation losses, especially major vegetation decline. As for the drought-vulnerable region, North China, particularly the central Inner Mongolia, is recognized with vegetation decline probabilities being 28.1% and 68.8% greater than the mainland average given drought conditions (quantified as SPEI ≤ −1), respectively. Results of the study may improve our understanding of climatic extreme influence on vegetation status and benefit the effective drought preparedness and mitigation.

The influence of environmental conditions (vegetation, temperature, equator, and elevation) on tropospheric nitrogen dioxide in urban areas in Indonesia

Nitrogen dioxide (NO2) is one important species in the tropospheric layer that has a contribution towards air quality. In urban areas in Indonesia, urbanization and growing industrial activities have increased rapidly, which may have affected tropospheric NO2. This study investigates the effect of green spaces and other environmental variables (e.g., temperature, city, distance from the equator) had on tropospheric NO2 in over thirty (30) urban areas in Indonesia between 2007 to 2016. Data on land cover were obtained from Google Earth’s satellite imagery data, tropospheric NO2 readings came from Metop-A, and information on temperature was obtained from the Terra MODIS satellite. Our results show an annual decrease in green space over 10 years in all urban areas except Surabaya. Multiple linear regression analysis also reveals that a decline in vegetation decreases tropospheric NO2 significantly. Other influential environmental factors are surface temperature and distance to the equator. Despite a promising model being obtained from this study, adding variables is important to improve the forecasting.

Spatiotemporal patterns of lithium mining and environmental degradation in the Atacama Salt Flat, Chile

Emerging electric-vehicle technologies and the global transition to renewable energy have driven the production of lithium batteries significantly in the past ten years. However, potential adverse impacts accompanying this transition require closer scrutiny. The purpose of this research is to assess the environmental impact and its possible correlation with lithium mining in the Atacama Salt Flat, the world’s largest lithium extraction site. Using both Landsat imagery and MODIS land products, we investigate the mining areas to (1) determine area and rate of change over time, (2) analyze spatiotemporal patterns of changes in key environmental parameters, and (3) perform regression analysis between lithium mining activities and environmental degradation between 1997 and 2017. We use five environmental parameters for our analysis: Normalized Difference Vegetation Index (NDVI), Daytime Land Surface Temperature (Day-LST), Soil Moisture Index (SMI), Nighttime Land Surface Temperature (Night-LST), and Net Evapotranspiration (ET). Our analysis shows that lithium mining operations have expanded rapidly by 7.07% annually. Our pixel-based time-series trend analysis for each image stack, using the Mann-Kendall test and Sen’s slope coefficient, shows some significant degradation over the past 20 years including (1) vegetation decline, (2) elevating daytime temperatures, (3) decreasing trend of soil moisture, and (4) increasing drought condition in national reserve areas. However, no substantial degradation in nighttime-LST and ET is observed in the study area. Our analyses of the relationship between mining activities and environmental degradation also indicate that the continuous expansion of lithium mining has strong negative correlations with the NDVI and SMI, and a strong positive correlation with LST. We identified lithium mining activities as one of the major stressors to the local environmental degradation. The results provide a baseline to evaluate future socio-environmental impacts of lithium mining in the region. We anticipate our analysis will help inform mining and environmental regulators, lithium industry decision-makers, and national park managers to provide better management of the world’s largest lithium production sites for a sustainable future.

Can We Detect the Brownness or Greenness of the Congo Rainforest Using Satellite-Derived Surface Albedo? A Study on the Role of Aerosol Uncertainties

The ability of spatial remote sensing in the visible domain to properly detect the slow transitions in the Earth’s vegetation is often a subject of debate. The reason behind this is that the satellite products often used to calculate vegetation indices such as surface albedo or reflectance, are not always correctly decontaminated from atmospheric effects. In view of the observed decline in vegetation over the Congo during the last decade, this study investigates how effectively satellite-derived variables can contribute to the answering of this question. In this study, we use two satellite-derived surface albedo products, three satellite-derived aerosol optical depth (AOD) products, two model-derived AOD products, and synthetic observations from radiative transfer simulations. The study discusses the important discrepancies (of up to 70%) found between these satellite surface albedo products in the visible domain over this region. We conclude therefore that the analysis of trends in vegetation properties based on satellite observations in the visible domain such as NDVI (normalized difference vegetation index), calculated from reflectance or albedo variables, is still quite questionable over tropical forest regions such as the Congo. Moreover, this study demonstrates that there is a significant increase (of up to 14%) in total aerosols within the last decade over the Congo. We note that if these changes in aerosol loads are not correctly taken into account in the retrieval of surface albedo, a greenness change of the surface properties (decrease of visible albedo) of around 8% could be artificially detected. Finally, the study also shows that neglecting strong aerosol emissions due to volcano eruptions could lead to an artificial increase of greenness over the Congo of more than 25% in the year of the eruptions and up to 16% during the 2–3 years that follow.

Impact of agrarian practices and some pastoral uses on vegetation in Algerian steppe rangelands

The decline in steppe vegetation in Algeria was first reported in the mid-20th century, and for many years was attributed to recurrent droughts. Hypotheses suggesting that this decline was a consequence of human activities emerged in the 1970s – a time of major socioeconomic trends in the region. Changes such as strong population growth, sedentarisation, herd size increases and use of pasture land for crops, all had considerable impact on rangeland vegetation. The aim of the present work was to identify heterogeneity in the pasture vegetation of a given ‘territory’ (in the sense of a ‘terroir’), or biophysical environment (including meteorological), taking into account rangeland distribution, land use changes and herd management in the Aflou region of Algeria. Characterisation and mapping of the vegetation and its environment in the study area led to the hypothesis that, apart from some very slight soil differences, heterogeneity in rangeland vegetation appeared mainly related to human impacts. Bertin’s Semiology of Graphics was used to analyse the results, and indicated a major decline in vegetation productivity and biodiversity in the steppe rangelands of the study zone. Beyond this general trend in the municipal territory studied, areas were found with contrasting flora communities, with some showing relatively stable plant communities, while other areas had some plant communities that had undergone regressive succession. Grazing conditions and the proximity of ploughed land were responsible for these different vegetation situations.

Estimating regional flood discharge during Palaeocene-Eocene global warming

Among the most urgent challenges in future climate change scenarios is accurately predicting the magnitude to which precipitation extremes will intensify. Analogous changes have been reported for an episode of millennial-scale 5 °C warming, termed the Palaeocene-Eocene Thermal Maximum (PETM; 56 Ma), providing independent constraints on hydrological response to global warming. However, quantifying hydrologic extremes during geologic global warming analogs has proven difficult. Here we show that water discharge increased by at least 1.35 and potentially up to 14 times during the early phase of the PETM in northern Spain. We base these estimates on analyses of channel dimensions, sediment grain size, and palaeochannel gradients across the early PETM, which is regionally marked by an abrupt transition from overbank palaeosol deposits to conglomeratic fluvial sequences. We infer that extreme floods and channel mobility quickly denuded surrounding soil-mantled landscapes, plausibly enhanced by regional vegetation decline, and exported enormous quantities of terrigenous material towards the ocean. These results support hypotheses that extreme rainfall events and associated risks of flooding increase with global warming at similar, but potentially at much higher, magnitudes than currently predicted.